Harris A, Ciulla T A, Chung H S, Martin B
Department of Opthalmology, Indiana University School of Medicine, Indianapolis, USA.
Arch Ophthalmol. 1998 Nov;116(11):1491-5. doi: 10.1001/archopht.116.11.1491.
Blood flow to the retina and optic nerve remains constant over a range of elevated intraocular pressure or mean arterial pressure, independent of sympathetic activation (pressure autoregulation). In addition, increased metabolic activity in these tissues proportionally increases blood flow (metabolic autoregulation). At constant metabolic rate, altered arterial oxygen content reciprocally alters blood flow, leaving total oxygen delivery constant, while blood flow rises and falls with the arterial carbon dioxide tension. These responses are similar to those of the cerebral circulation. However, while aging, atherosclerosis, arterial hypotension, and individual variation may profoundly alter blood flow regulation and predispose to the development of illness, these factors remain largely unexplored.
在一定范围内的眼压升高或平均动脉压升高情况下，视网膜和视神经的血流保持恒定，与交感神经激活无关（压力自动调节）。此外，这些组织中代谢活动的增加会相应地增加血流（代谢自动调节）。在代谢率恒定的情况下，动脉血氧含量的改变会反向改变血流，使总氧输送量保持恒定，而血流则随动脉二氧化碳张力的升降而增减。这些反应与脑循环的反应相似。然而，尽管衰老、动脉粥样硬化、动脉低血压和个体差异可能会深刻改变血流调节并易引发疾病，但这些因素在很大程度上仍未得到充分研究。
